p38 (IC50 = 50 nM); p38β2 (IC50 = 500 nM)

SB203580 has an IC50 of 3-5 μm and blocks the proliferation of primary human T cells, murine CT6 T cells, or BAF F7 B cells when IL-2 is present. Although the concentration needed is a little bit higher and the IC50 is above 10 μM, SB203580 also inhibits IL-2-induced p70S6 kinase activation. With an IC50 in the 3-10 μM range, SB203580 also inhibits the activity of PDK1 in a dose-dependent manner. MAPKAPK2 stimulation by p38-MAPK is inhibited by SB203580 with an IC50 of roughly 0.07 μM, whereas total SAPK/JNK activity is inhibited with an IC50 of 3–10 μM. Higher concentrations of SB203580 cause the ERK pathway to be activated, which then improves the transcriptional activity of NF-κB. Human hepatocellular carcinoma (HCC) cells are induced to undergo autophagy by SB203580.

SB203580 protects the pig myocardium in an in vivo model from ischemic damage. In the MRL/lpr mouse model of systemic lupus erythematosus (SLE), SB203580 is effective in preventing and treating the illness.

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Proteinuria is prevented in SB203580 treated MRL/lpr mice. [4]
ALT and AST are not influenced by SB203580 in MRL/lpr mice. [4]
BUN but not Cr is decreased in SB203580 treated MRL/lpr mice. Renal but not splenic weight is reduced in SB203580 treated MRL/lpr mice. [4]
Renal pathologic changes are attenuated in SB203580 treated MRL/lpr mice. [4]
Hepatic pathologic changes are relieved in SB203580 treated MRL/lpr mice. [4]
Splenic pathologic changes are relieved in SB203580 treated MRL/lpr mice. [4]
Glomerular IgG, IgM, IgA and C3 depositions are reduced in SB203580 treated MRL/lpr mice. [4]

4 μg of sheep anti-PKBα is immobilized on 25 μL of protein G-Sepharose overnight (or 1.5 hours) and washed in Buffer A (50 mm Tris, pH 7.5, 1 mm EDTA, 1 mm EGTA, 0.5 mm Na3VO4, 0.1% β-mercaptoethanol, 1% Triton X-100, 50 mm sodium fluoride, 5 mm sodium pyrophosphate, 0.1 mm phenylmethylsulfonyl fluoride, 1 μg/mL aprotinin, pepstatin, leupeptin, and 1 μm microcystin). The immobilized anti-PKB is then incubated with 0.5 ml of lysate (from 5 × 106 cells) for 1.5 hours and washed three times in 0.5 mL of Buffer A supplemented with 0.5 m NaCl, two times in 0.5 mL of Buffer B (50 mm Tris-HCl, pH 7.5, 0.03% (w/v) Brij-35, 0.1 mm EGTA, and 0.1% β-mercaptoethanol), and twice with 100 μl of assay dilution buffer; 5× assay dilution buffer is 100 mm MOPS, pH 7.2, 125 mm β-glycerophosphate, 25 mm EGTA, 5 mm sodium orthovanadate, 5 mm DTT. To the PKB enzyme immune complex is added 10 μL of assay dilution buffer, 40 μm protein kinase A inhibitor peptide, 100 μm PKB-specific substrate peptide, and 10 μCi of [γ-32P]ATP, all made up in assay dilution buffer. The reaction is incubated for 20 minutes at room temperature with shaking, then samples are pulse spun, and 40 μL of reaction volume are removed into another tube to which is added 20 μL of 40% trichloroacetic acid to stop the reaction. This is mixed and incubated for 5 minutes at room temperature, and 40 μL is transferred onto P81 phosphocellulose paper and allowed to bind for 30 seconds. The P81 piece is washed three times in 0.75% phosphoric acid then in acetone at room temperature. γ-32P incorporation is then measured by scintillation counting.

In the absence of growth factors, antibiotics, or β-mercaptoethanol supplements, CT6 cells and BA/F3 F7 cells are rested by washing three times in RPMI and culturing overnight in RPMI with 5% fetal calf serum. Preincubation with SB203580 or a vehicle control, as indicated in the figure legends, is performed on 2-5 106 rested CT6 cells in 2 mL of RPMI, 5% fetal calf serum. Following a 5-minute incubation period at 37 °C with 20 ng/ml recombinant human IL-2 stimulation, cells are pelleted in a minifuge for 30 seconds, the medium is aspirated, and the pellet is lysed in the proper buffer. BA/F3 cells are maintained in glutamine-containing RPMI that is additionally supplemented with 5% fetal calf serum and 0.2 μg/mL G418 and stably express deletion mutants of the IL-2 β receptor chain. The cells are then thoroughly washed, allowed to rest for the night, and then washed once more before being activated with IL-2. Such cell preparations contain >90% T cells. The incorporation of [3H]thymidine is measured in cellular proliferation assays.

Six-week-old female atymic Nu/Nu mice CAL27 p38WT and p38TM tumors[1]
5 mg/kg/day
Intra peritoneal injected daily for 16 consecutive days

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Systemic lupus erythematosus (SLE) are established in female MRL/lpr mice and female C57BL/6 mice
0.1 M/day
Orally administered

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Female MRL/lpr mice were randomized into two groups (n = 10 per group) and were fed control diet (named as group 2 in the following) or diet with SB203580 (named as group 3 in the following) starting at the age of 14 weeks and continuing for up to 22 weeks. Adezmapimod (SB203580) was dissolved in drinking water (250 μmol/L), was orally administered (0.4 ml/day). Ten C57BL/6 female mice were used as negative controls (named as group 1 in the following). Two mice in MRL/lpr group 2 were dead at 16 weeks and 18 weeks of age respectively. Two mice in MRL/lpr group 3 were dead at 19 weeks of age. Significant increase of urine protein (300–2000 mg/dl) was found in each mouse before death, indicating a probable renal failure be the cause of death. Ultimately, 10 mice in group 1, 8 mice in group 2 and group 3 were included in statistical analysis.[4]

[1]. Specificity and mechanism of action of some commonly used protein kinase inhibitors. Biochem J. 2000 Oct 1;351(Pt 1):95-105.

[2]. The pyridinyl imidazole inhibitor SB203580 blocks phosphoinositide-dependent protein kinase activity, protein kinase B phosphorylation, and retinoblastoma hyperphosphorylation in interleukin-2-stimulated T cells independently of p38 mitogen-activated protein kinase. J Biol Chem. 2000 Mar 10;275(10):7395-402.

[3]. A role for p38 MAPK in head and neck cancer cell growth and tumor-induced angiogenesis and lymphangiogenesis. Mol Oncol. 2014 Feb;8(1):105-18.

[4]. The selective p38 mitogen-activated protein kinase inhibitor, SB203580, improves renal disease in MRL/lpr mouse model of systemic lupus. Int Immunopharmacol. 2011 Sep;11(9):1319-26.

Pyridinyl imidazole inhibitors, particularly SB203580, have been widely used to elucidate the roles of p38 mitogen-activated protein (MAP) kinase (p38/HOG/SAPKII) in a wide array of biological systems. Studies by this group and others have shown that SB203580 can have antiproliferative activity on cytokine-activated lymphocytes. However, we recently reported that the antiproliferative effects of SB203580 were unrelated to p38 MAP kinase activity. This present study now shows that SB203580 can inhibit the key cell cycle event of retinoblastoma protein phosphorylation in interleukin-2-stimulated T cells. Studies on the proximal regulator of this event, the phosphatidylinositol 3-kinase/protein kinase B (PKB)(Akt/Rac) kinase pathway, showed that SB203580 blocked the phosphorylation and activation of PKB by inhibiting the PKB kinase, phosphoinositide-dependent protein kinase 1. The concentrations of SB203580 required to block PKB phosphorylation (IC(50) 3-5 microM) are only approximately 10-fold higher than those required to inhibit p38 MAP kinase (IC(50) 0.3-0.5 microM). These data define a new activity for this drug and would suggest that extreme caution should be taken when interpreting data where SB203580 has been used at concentrations above 1-2 microM.[2]

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We have recently gained a remarkable understanding of the mutational landscape of head and neck squamous cell carcinoma (HNSCC). However, the nature of the dysregulated signaling networks contributing to HNSCC progression is still poorly defined. Here, we have focused on the role of the family of mitogen activated kinases (MAPKs), extracellular regulated kinase (ERK), c-Jun terminal kinase (JNK) and p38 MAPK in HNSCC. Immunohistochemical analysis of a large collection of human HNSCC tissues revealed that the levels of the phosphorylated active form of ERK1/2 and JNK were elevated in less than 33% and 16% of the cases, respectively. Strikingly, however, high levels of active phospho-p38 were observed in most (79%) of hundreds of tissues analyzed. We explored the biological role of p38 in HNSCC cell lines using three independent approaches: treatment with a specific p38 inhibitor, SB203580; a retro-inhibition strategy consisting in the use of SB203580 combined with the expression of an inhibitor-insensitive mutant form of p38α; and short-hairpin RNAs (shRNAs) targeting p38α. We found that specific blockade of p38 signaling significantly inhibited the proliferation of HNSCC cells both in vitro and in vivo. Indeed, we observed that p38 inhibition in HNSCC cancer cells reduces cancer growth in tumor xenografts and a remarkable decrease in intratumoral blood and lymphatic vessels. We conclude that p38α functions as a positive regulator of HNSCC in the context of the tumor microenvironment, controlling cancer cell growth as well as tumor-induced angiogenesis and lymphangiogenesis.[3]

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Systemic lupus erythematosus (SLE) is an autoimmune disease accompanying excessive inflammatory responses in a wide range of organs. Abnormal activation of p38 MAPK has been postulated to contribute to the inflammation of SLE, leading to progressive tissue and organ damages to develop lupus nephritis and autoimmune hepatitis. In order to determine whether p38 MAPK inhibitor is effective in mouse model of SLE, a specific inhibitor of p38 MAPK SB203580 was orally administrated to MRL/lpr mice aged from 14 to 22 weeks. Renal and hepatic functions, as well as pathologic changes of important organs including kidney, liver and spleen of MRL/lpr mice were evaluated. As a result, we showed that SB203580 improved renal function by decreasing the levels of proteinuria and serum BUN, ameliorating the pathologic changes of kidney and reducing Ig and C(3) depositions in the kidney. Hepatocytes necrosis, recruitment and proliferation of leucocytes in liver and spleen were found to be inhibited by administration of SB203580. Therefore, p38 MAPK activation may be partially responsible for escalating autoimmune renal, hepatic and splenic destruction, and its inhibitor may lighten the autoimmune attack in these important organs and improve renal function. Our study reveals that the selective blockade of p38 MAPK is effective to prevent and treat the disease in this model of SLE.[4]

C₂₁H₁₇CLFN₃OS

413.90

413.076

C, 60.94; H, 4.14; Cl, 8.56; F, 4.59; N, 10.15; O, 3.87; S, 7.75

869185-85-3

Adezmapimod;152121-47-6

16760644

Light yellow to yellow solid powder

6.349

2

5

4

28

500

0

Cl.O=S(C)C1C=CC(C2NC(C3C=CC(F)=CC=3)=C(C3C=CN=CC=3)N=2)=CC=1

WOSGGXINSLMASH-UHFFFAOYSA-N

InChI=1S/C21H16FN3OS.ClH/c1-27(26)18-8-4-16(5-9-18)21-24-19(14-2-6-17(22)7-3-14)20(25-21)15-10-12-23-13-11-15;/h2-13H,1H3,(H,24,25);1H

4-[4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-1H-imidazol-5-yl]pyridine;hydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.04 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (6.04 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: 4% DMSO+30% PEG 300+5% Tween 80+ddH2O: 5mg/mL

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 (Please use freshly prepared in vivo formulations for optimal results.)